Privileged structures are molecular frameworks exhibited in natural products and medicinal compounds that show therapeutic activity at number of different receptor or enzyme targets. Accordingly, facile enantioselective synthetic routes to such structures are valuable and are in constant demand.
Two such privileged structures are Dihydroisocoumarins (A) and Dihydroisoquinolinones (B). The asterisks denote carbon atoms that are chiral. Given the effect the chirality of these stereogenic carbons may have on the activity of these molecules, controlling the absolute stereochemistry of the substituents on these carbon atoms is.

Molecules possessing the bicyclic dihydroisocoumarin structural unit exhibit broad spectrum activity and have been reported as cytotoxic/antiproliferative agents, phytotoxic agents, antimicrobial agents, antifungal agents, antiulcer agents, antimalarial agents, anti-inflammatory agents, antioxidant agents and antiallergic properties.
For example, European Patent Application No. 2 301 931 discloses a class of chiral dihydroisocoumarins functionalised with imidazoles (C):

The compounds are indicated as being clinically useful in the treatment of diseases mediated by abnormal activity of aldosterone synthase, such as coronary heart disease or renal failure.
European Patent Application No. 2 301 931 discloses two separate routes to the compounds of interest, neither of which readily lends itself to an enantioselective variant. In particular, EP2 301 931 discloses the resolution of the racemic compounds by means of methods known in the art, such as diastereomeric crystallisation and chiral HPLC. Naturally, discarding the unwanted enantiomer is wasteful and a more elegant enantioselective synthesis would be preferable.
Accordingly, there remains a need for alternative synthetic routes to these, and other privileged heterocyclic structures in which the chirality of any stereogenic carbons can be readily controlled.
Bassas et al. (Eur. J. Org. Chem. 2009, 1340) employed a bifunctional organocatalyst, to catalyse the conjugate addition of Meldrum's acid (a cyclic ester) to a nitroalkene, in a synthesis of Pregabalin.
Shi et al. (Tetrahedron, 2011, 67, 1781) employed a bifunctional organocatalyst, to catalyse a three-component Knoevanagel-Diels-Alder addition reaction involving enones aldehydes and Meldrum's acid (a cyclic ester).